The AreaLimiter allows to specify a selection area, either a polygon or a bounding box, the condition geometries have to meet in regards to the to be loaded (contained in area or intersecting the area) and how selected geometries will be loaded (full geometry or only the parts inside the area).

In this example we use an existing feature class with polygons and dowload features from a layers feature class with an area limiter.

import GSTPy
from pathlib import Path

# base dir where we want to store the output
base_dir = Path(r"D:\temp\area_limiter")
# define a fixed load mode and threshold for the whole operation
# selected features will load the part inside the selection area
load_mode = GSTPy.GeometryLoadMode.Partial
# only load features, if they intersect the selection area
load_threshold = GSTPy.GeometryLoadThreshold.Intersected
# download format will be Gocad
request_format = GSTPy.RequestFormat.GCD
# Get all feature classes
feature_classes = ni.list_feature_classes()
# Store the polygon feature class
polygon_feature_class = next(
    (fc for fc in feature_classes
     if fc.owner_name == "EVERYBODY_pool" and == "polygons"))
# Store the layer feature class
layer_feature_class = next(
    (fc for fc in feature_classes
     if fc.owner_name == "EVERYBODY_pool" and == "layers"))
# loop through each polygon feature of the polgyon feature class
print("Starting download.")
# retrieve the polygon features
polygon_features = ni.list_features(polygon_feature_class)
for polygon_feature in polygon_features:
    # define our selection area to be the current polygon_feature
    area = GSTPy.Area(GSTPy.PolygonSelection(polygon_feature))
    # define the area limiter with the selection area and our defined load
    # mode and threshold
    area_limiter = GSTPy.AreaLimiter(area, load_mode, load_threshold)
    # define download dir to
    # "base_dir / the layer feature class / polygon feature with feature class"
    # note: the filename will be set by GST to the (sanitized) feature name
    polygon_feature_full_name = polygon_feature_class.full_name + "." +
    download_dir = base_dir / layer_feature_class.full_name / polygon_feature_full_name
    # create the download dir on the filesytem
    download_dir.mkdir(parents=True, exist_ok=True)
    # loop through all layers and save them to the download dir with the above
    # area  limiter
    print(f"  Starting download with polygon {}.")
    # retrieve the layers
    layers = ni.list_features(layer_feature_class)
    for layer in layers:
        print(f"    Starting download layer {}...",
        # to not abort on the first error, we wrap this call in a try..except
        # block and print the error
        # note: trying to dowload a feature that is rejected by the area
        # limiter, e.g. if it is not inside the area, will also raise an
        # exception
        except Exception as e:
            print(f"Failure: {e}.")
    print(f"  Finished download with polygon {}.")
print("Finished download.")